Prognostic value of ALDH2 polymorphism for patients with oropharyngeal cancer in a Japanese populationPrognostic value of ALDH2 polymorphism for patients with oropharyngeal cancer in a Japanese population

Background Half of Japanese possess a polymorphism of aldehyde dehydrogenase 2(ALDH2), while few white individuals possess this mutation. The purpose of this study was to investigate the possibility of ALDH2 polymorphism as a prognostic factor for oropharyngeal cancer (OPC) among Japanese population. Methods We analyzed 82 Japanese patients with OPC treated between 2006 and 2011. The median observation period was 50 months. P16-staining and ALDH2 polymorphisms were investigated. To examine the frequencies of second primary pharyngeal and esophageal cancers (SPPEC), 37 Japanese patients with OPC treated at Tokyo University Hospital were included for statistical analysis. Results Statistically significant differences were noted in OS among sex, age, N classification, and p16 (p = 0.045, 0.024, 0.020, 0.007, respectively). In addition, OS and DSS rates of the patients with heterozygous ALDH2 tended to be worse than those of the patients with homozygous ALDH2 (p = 0.21, 0.086, respectively). Of note, OS and DSS of the patients with p16-negative OPC and heterozygous ALDH2 was significant poorer than those of the patients with p16-positive OPC (p = 0.002, 0.006, respectively), while there was no significant difference in OS and DSS between patients with p16-positive OPC and patients with p16-negative OPC and homozygous ALDH2. Conclusions ALDH2 polymorphism might be a promising prognostic factor for Japanese patients with p16-negative OPC.